Process for producing anionic metal-containing sulfonates

ABSTRACT

A PROCESS FOR PRODUCING ANIONIC METAL-CONTAINING FONATES IS DISCLOSED WHEREIN AN ANIONIC METAL-CONTAINING ACID IS REACTED WITH AN OIL-SOLUBLE SULFONIC ACID AND AN AMINO-ALCOHOL IN THE PRESENCE OF A NONVOLATILE CARRIER AND WATER.

United States Patent O Int. Cl. Cm N40 US. Cl. 252-33 9 Claims ABSTRACTOF THE DISCLOSURE A process for producing anionic metal-containingsulfonates is disclosed wherein an anionic metal-containing acid isreacted with an oil-soluble sulfonic acid and an amino-alcohol in thepresence of a nonvolatile carrier and water.

BACKGROUND OF THE INVENTION This invention relates to anionic metalsulfonates. In one aspect the invention relates to a process forproducing anionic metal sulfonates. In another aspect the presentinvention relates to a method for producing anionic metal sulfonatesfrom anionic metal containing acids. In still another aspect the presentinvention relates to the production of anionic metal sulfonates byreacting an anionic metal containing acid with an oil-soluble sulfonicacid and an amino-alcohol in the presence of a nonvolatile carrier andwater. In yet another aspect the present invention relates to theproduction of a boron-containing sufonate from boric acid, anoil-soluble sulfonic acid, and an amino-alcohol containing from 1 toabout 20 carbon atoms in the presence of a nonvolatile carrier andwater.

BRIEF DESCRIPTION OF THE PRIOR ART In recent years it has been foundthat superior standards .for spectrographic equipment can be preparedfrom oil-soluble metal sulfonates and metal dispersions in suchsulfonates by dissolving such material in predetermined quantities in asuitable solvent. Such standards have exhibited indefinite shelf lifeand any combination of metals can be combined without precipitation ofthe metal constituents.

Further, dispersions containing certain anionic metal sulfonates haveacquired considerable importance as additives in fuels and lubricatingoil. Such dispersions have been highly useful as additives to othermaterials where the problem of suspending insoluble waste materialsformed in the utilization of the material and also the problem ofcorrosion inhibition is met. When the anionic metal sulfonates areemployed as additives for use in internal combustion engine lubricatingcompositions such agents function to effectively disperse or peptize theinsolubles formed by the fuel combustion, oil oxidation, or similarconditions obtained during the operationof the engine.

Thus, while the use of anionic metal sulfonates have been establishedand recognized, problems have been encountered in the production of suchanionic metal sulfonates. For example, it has long been felt thatbecause of borons anionic properties sulfonates of such would have to beprepared as a binary mixture with another metal. As a result, thecalcium carbonate dispersions were 3,785,976 Patented Jan. 15, 1974converted to calcium borate dispersions and this product was used as theboron standard, such is not desirable because of the large quantities ofother metals required to carry the boron. Therefore, a need has longbeen recognized for an improved process for the production of anionicmetal sulfonates from readily available chemical compounds, and it is tosuch a process that the present invention is directed.

OBJECTS OF THE INVENTION An object of the present invention is toprovide an improved process for the production of anionic metalsulfonates. Another object of the present invention is to provide aneconomical, dependable, and efficient method for preparing anionic metalsulfonates from readily available chemical compounds. Another object ofthe present invention is to provide an improved method for thepreparation of boron-containing sulfonate which is suitable as ananalytical standard while at the same time providing an oil-solublesource of boron.

These and other objects, advantages, and features of the presentinvention would be apparent to those skilled in the art from a readingof the following detailed description.

SUMMARY OF THE INVENTION According to the present invention I have founda process for producing anionic metal-containing sulfonates whichbasically involves reacting an anionic metal-containing acid with anoil-soluble sulfonic acid, and an amino-alcohol in the presence of anonvolatile carrier and water.

Further, according to the invention, I have found that aboron-containing sulfonate can readily be prepared from boric acid byreacting the boric acid with an oilsoluble sulfonic acid and anamino-alcohol containing from 1 to about 20 carbon atoms, in anonvolatile carrier and water. A volatile inert solvent can beincorporated with the oil-soluble sulfonic acid to reduce the viscosityof same and to facilitate the admixing of the oil-soluble sulfonic acidwith the other constituents of the reaction mixture.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Anionic metal-containingsulfonates have been recognized as desirable analytical standards aswell as oilsoluble additives for fuels and lubricants. However, problemshave been encountered in producing such sulfonates. I have now foundthat anionic metal-containing acids can readily be converted to ananionic metal-containing sulfonate by a novel process which basicallyinvolves reacting the anionic metal-containing acid with an oilsolublesulfonic acid and an amino-alcohol containing 1 to about 20 carbonatoms, in the presence of a nonvolatile carrier, and water. The presentinvention can be carried out in either a batch-type process or acontinuous process. However, for the sake of simplicity, the process ofthe present invention will be described as a batch-type process.

In a batch-type process the anionic metal-containing acid, theamino-alcohol, the oil-soluble sulfonic acid, the

nonvolatile carrier, and the water are charged to a reaction vesselwhich is equipped with stirring and heating means. The amount ofreactants employed will vary widely but the amino-alcohol constituent isadded in at least a stoichiometric amount based on the oil-solublesulfonic acid whereas the anionic metal-containing acid is added inabout a stoichiometric amount based on the amount of amino-alcoholemployed. The amount of nonvolatile carrier employed is dependent solelyupon the viscosity of the product desired. Generally, however, theamount of nonvolatile carrier will range from about 10 to 70 weightpercent, based on the total reaction mixture. Likewise, the amount ofwater employed can vary broadly but will generally be present in anamount ranging from about 5% to 50% by weight. Once the reactants havebeen introduced into the reaction vessel the reactants are thoroughlyagitated and the reaction mixture is heated to the reflux temperaturewhich will generally be within the range of about 50 degrees C. to about125 degrees C. The heating period is carried out slowly so as to be overa period of time from about 1 hour to hours. During this heating periodthe volatile components, including the water are removed. An additionalamount of the nonvolatile carrier compound can then be added to thereaction mixture and the mixture heated to a temperature within therange of about 125 degrees C. o 175 degrees C. The amount of additionalnonvolatile carrier employed will vary widely but will generally rangefrom about 10 to 50 percent by weight of the amount of the volatilesolvent originally employed. During this second heating step the productis stripped with an inert gas, such as nitrogen, carbon dioxide, orhelium for a period of time ranging from about minutes to 3 hours.

Additional purification steps, such as polish filtering the product canbe employed. In addition when a highly pure product is desired oneshould use distilled water as the water constituent. The productobtained contains from about 10 to 90 weight percent of the anionicmetal-containing sulfonate in the nonvolatile carrier. In addition itshould be evident that other inert solvents can be employed tofacilitate the mixing of the reactants during both the initial heatingperiod and the second or subsequent heating period. For example, theoil-soluble sulfonic acid can be diluted with from about 10 to 80 weightpercent of a volatile solvent such as petroleum naphtha hydrocarbons,such as hexane, heptane, octane, toluene, benzene or xylene. The use ofsuch volatile solvents is merely to enhance the mixability of thesulfonic acid constituent into the reaction mixture and the solvent willbe stripped due to the steps incurred in the process as described above.

In practicing the process of the present invention for the preparationof anionic metal sulfonates from anionic metal-containing acids, anysuitable anionic metal-containing acid can be employed. Examples ofsuitable anionic metal constituents which can be employed in the acidare boron, silicon, phosphorus, arsenic, selenium and vanadium.Desirable results have been obtained wherein boric acid is employed asthe anionic metal-containing acid.

The amino-alcohols which are suitable for use in the process of thepresent invention are represented by the general formula NR wherein R isH, C,,H ,,OH, OH, C H NH and mixtures thereof and n is an integer offrom 1 to 20. Desirable results have been obtained wherein the alkylradical contains from 1 to about 8 carbon atoms. Further, theamino-alcohol is one in which the anionic metal-containing acidconstituent and the oil-soluble sulfonic acid have an appreciablesolubility. Examples of suitable amino-alcohols falling within theabove-defined limits are: ethanol amine, diethanol amine, triethanolamine, propanol amine, dipropanol amine, 2- methyl 2-amino propanediol,2,3-dimethyl 2-amino 1,4- butanediol, butyl-amino alcohols, hepta-,hexa-amino alcohols, etc., branched amino diols, branched amino triols,etc.

Suitable oil-soluble hydrocarbon sulfonic acids include alkane sulfonicacid, aromatic sulfonic acid, alkaryl sulfonic acid, dialkaryl sulfonicacids, aralkyl sulfonic acid, and the natural petroleum mahoganysulfonic acids. The mahogany sulfonic acids include any of thosematerials which may be obtained by concentrated or fuming sulfuric acidtreatment of petroleum fractions, particularly the higher boilinglubricating oil distillates and white oil distillates. The highermolecular weight petroleum oilsoluble mahogany sulfonic acids arecondensed-ring compounds, which condensed-rings may be aromatic orhydroaromatic in nature. Alkyl and/ or cycloalkyl su bstituents may bepresent in the mahogany sulfonic acids.

The term oil-soluble sulfonic acids," as used herein, refers to thosematerials wherein the hydrocarbon portion of the molecule has amolecular weight in the range of about 300 to about 1,000. Preferably,this molecular weight is in the range of about 370 to about 700. Theseoil-soluble sulfonic acids can be either synthetic sulfonic acids or theso-called mahogany or natural sulfonic acids. The term mahogany sulfonicacids refers to those materials which are prepared by sulfonation ofhydrocarbon feedstocks which are prepared synthetically. The syntheticsulfonic acids can be derived from either alkyl or alkaryl hydrocarbons.in addition, they can be derived from hydrocarbons having cycloalkyl(i.e., naphthenic) groups in the side chains attached to the benzenering. The alkyl groups in the alkaryl hydrocarbons can be straight orbranched chain. The alkaryl radical can be derived from benzene,toluene, ethyl benzene, xylene isomers, or naphthalene.

An example of a hydrocarbon feedstock which has been particularly usefulin preparing synthetic sulfonic acids is a material known aspostdodecylbenzene. Postdodecylbenzene is a bottoms product of themanufacture of dodecylbenzene. The alkyl groups of postdodecylbenzeneare branched chain. Postdodecylbenzene consists of monoalkylbenzenes anddialkylbenzenes in the approximate mole ratio of 2:3 and has typicalproperties as follows:

Specific gravity at 38 degrees C 0.8649 Average molecular weight 385Percent sulfonatable 88 ASTM D-15 8 Engler:

I.B.P. degrees F. 647 5 degrees F. 682. 50 degrees F. 715 90 degrees F.760 degrees F. 775 F.B.P. degrees F. 779 Refractive index at 23 degreesC. 1,4900 Viscosity at:

10 degrees C., centistokes 2800 20 degrees C., centistokes 280 40degrees C., centistokes 78 80 degrees C., centistokes 18 Aniline point,degrees C 69 Pour point, degrees F. 25

An example of another hydrocarbon feedstock which is particularly usefulin preparing synthetic sulfonic acids is a material referred to as dimeralkylate. Dimer alkylate has a long, branched-chain alkyl group. Brieflydescribed, dimer alkylate is prepared by the following steps:

(1) dimerization of a suitable feedstock, such as cat poly gasoline.

(2) alkylation of an aromatic hydrocarbon with the dimer formed in step(1).

Preferably, the dimerization step uses a Friedel-Crafts alkylationsludge as the catalyst. This process and the resulting product aredescribed in U.S. Pat. No. 3,410,925.

An example of another hydrocarbon feedstock which is particularly usefulfor preparing synthetic sulfonic acids which can be used in my inventionis a material which I refer to as NAB Bottoms." NAB Bottoms arepredominantly di-n-alkyl aromatic hydrocarbon wherein the alkyl groupscontain from 8 to 18 carbon atoms. They are distinguished primarily fromthe preceding sulfonation feedstocks in that they are straight chain andcontain a large amount of di-substituted material. A process ofpreparing these materials and the resulting product are described inapplication Ser. No. 62,211, filed Aug. 7, 1970, and being acontinuation-in-part of application Ser. No. 529,284, filed Feb. 23,1966, and now abandoned. Application Ser. Nos. 62,211 and 529,284 havethe same assignee as the present application. The product is alsodescribed in U.S. Pat. No. 3,288,716, which is concerned with anadditional use for the product, other than sulfonation feedstock.Another process of preparing these materials is described in applicationSer. No. 53,352, filed Aug. 6, 1970, and having the same assignee as thepresent application. Application Ser. No. 53,352 is acontinuation-in-part of application Ser. No. 529,284. Still anotherprocess of preparing a di-n-alkaryl product is described in applicationSer. No. 104,476, filed Jan. 7, 1971, which is a continuation-in-part ofapplication Ser. No. 521,794, filed Jan. 20, 1966, and now abandoned.

In order to make my disclosure even more complete, US. Pat. No.3,410,925 and application Ser. Nos. 53,352; 62,211 and 104,476 are madea part of this disclosure.

In addition to the sulfonic acids derived from the foregoing describedhydrocarbon feedstock, examples of other suitable sulfonic acids includethe following: monoand poly-wax-substituted naphthalene sulfonic acid,dinonyl naphthalene sulfonic acid, diphenyl ether sulfonic acid,naphthalene disulfide sulfonic acid, dicetyl thianthrene sulfonic acid,dilauryl betanaphthol sulfonic acid, dicapryl nitronaphthalene sulfonicacid, unsaturated paraflin wax sulfonic acid, hydroxy substitutedparaffin wax sulfonic acid, tetraamylene sulfonic acid, monoandpoly-chlorosubstituted paraflin wax sulfonic acid, nitrosoparaflin waxsulfonic acid, cycloaliphatic sulfonic acid such as laurylcyclohexylsulfonic acid, monoand poly-wax-substituted cyclohexyl sulfonic acid,and the like.

In order to disclose more clearly the nature of the present invention,the following example is given. It is to be understood that the exampleis for illustrative purposes only and is not to be construed as unduelimitations upon the invention.

Example I A twelve-liter, 3-neck flask was charged with the following:

G. Sulfonic acid 1 in hexane 5,000 Triethanol amine 810 Distilled water1,000 Boric acid 355 80 pale oil 1,000

A disproportionated dialkyl benzene sulfonlc acid having the followingproperties Total acidity 1.015 meqs./gm. Sulfonic acidity 0.953 mega/gm.Percent non v01 52 4 i 0 a Molecular weight of sultonic acid 500 grams(avg). Percent hexane 47.6%.

A disproportionated dialkyl benzene snlfonlc acid having the followingproperties Total acidity 1.089 meqs./gm. Sulfonic acidity 1.035 megs/gm.Percent nonvolatile 47.1 0. Percent hexane 52.9% Molecular weight ofsulfonic acid 489 grams (avg).

The above was well mixed and the mixture was heated slowly and thesolvents were removed to 150 degrees C. (over about 2 hours). Theproduct became bright and clear at about degrees C. At degrees C. themixture was stripped with carbon dioxide for about 20 minutes. Theproduct was polish filtered and determined to contain 1.0 percent boron.

The above example clearly indicates the preparation of an anionic metalsulfonate by the process of the present invention.

Having thus described the invention, I claim:

1. A process for producing anionic metal sulfonates which comprises:

(a) admixing an anionic metal-containing acid, wherein the metalconstiutent of said acid is selected from the group consisting of boron,arsenic, selenium and vanadium, an amino-alcohol having from 1 to about20 carbon atoms, an oil-soluble sulfonic acid, from about 5 to 50 weightpercent water and from about 10 to 70 weight percent nonvolatile carrierto form a reaction mixture, said anionic metal-containing acid beingpresent in about a stoichiometric amount with said amino-alcohol andsaid amino-alcohol being present in at least a stoichiometric amountwith said oil-soluble sulfonic acid;

(b) heating said reaction mixture to the reflux temperature of saidmixture and then removing the volatile components therefrom therebyforming a stripped mixture;

(0) heating said stripped mixture to a temperature in the range of about125 to about degrees C. for a period of time ranging from about 20minutes to 2 hours; and

(d) recovering the nonvolatile carrier containing from about 10 to 90weight percent anionic metal sulfonate.

2. The process of claim 1 which includes the step of admixing from about10 to 50 weight percent of additional nonvolatile carrier to saidstripped mixture, said carrier being the same employed in said reactionmixture.

3. The process of claim 2 wherein said amino-alcohol is represented bythe general formula NR wherein R is selected from the group consistingof H, C,,H OH, OH, C H NH and mixtures thereof and wherein n is aninteger of from 1 to 20.

4. The process of claim 3 wherein said alkyl radical of saidamino-alcohol contains from 1 to about 8 carbon atoms and wherein saidreflux temperature is from about 50 to 125 degrees C. and is carried outslowly over a period of time of from about 1 hour to 10 hours.

5. The process of claim 4 which includes the step of contacting saidstripped mixture during the heating of same with an inert gas for aperiod of time of from about 20 minutes to 3 hours.

6. The process of claim 5 which includes the step of polish filteringthe nonvolatile carrier-anionic metal sulfouate product.

7 8 7. The process of claim 6 wherein said water is dis- ReferencesCited tilled water, and said nonvolatile carrier is a pale oil. UNITEDSTATES PATENTS p s of dam 7 Wherem sald ec o 3,219,580 11/1965 Stratum252 33 1s methanol amlne and sald oll-soluhle sulfonlc acid 15 2,889,2796/1959 Carlyle et all 252 33 an dialkaryl sulfonlc acid diluted withfrom about 10 5 3,535,242 10/1970 Hashimoto et aL to 80 weight percenthexane, said alkaryl sulfonic acid 2 0 72 3 1952 Gasser et a]. having amolecular weight in the range of about 300 to 2,947,694 8/1960 Gragson25233.4 1000'. 3,277,002 10/1966 Hunt et a1. 25233.4

9. The process of claim 7 wherein said amino-alcohol 10 is 2-methy1,Z-amino propanediol and said oil-soluble DANIEL M Pnma'ry Exammersulfonic acid is an alkaryl sulfonic acid diluted with from VAUGHN,Assistant Exammel' about 10 to 80 weight percent hexane, said alkarylsul- U S C1 X R fonic acid having a molecular weight in the range of 154468, 76; 252-463; 260429 K, 440, 462, 607

